(a) Field of the Invention
The present invention relates to an oil tank floating roof device, and more particularly to a floating device applied to the liquid surface of oil stored in a tank, using longitudinal or crosswise insertion joint connections to produce stable and pressure resistant joining areas while reducing assembly cost.
(b) Description of the Prior Art
Regarding oil tank structures for oil storage of the prior art, apart from hollow tanks being used for oil storage, moreover, floating roof equipment must also be disposed in the oil tank, the floating roof equipment being used to float and cover the liquid surface of the oil stored in the oil tank, thereby enabling upward or downward displacement of the floating roof equipment along with a rise or fall of the height of the liquid level of the stored oil, and a sealed top surface of the oil tank top is used to reduce emissions form the storage of volatile organic compounds. Republic of China patent No. 201008850 entitled “Fuel Tank Floating Roof Device”, discloses a floating roof equipment for oil storage tank typical of the prior art, and such a floating roof equipment forms fixed edge fittings with the casing of floating units. In which each of the floating units forms overlapping locking connections between longitudinal frame bars, crosswise frame bars by means of fixed joined edges. Such a configuration requires that the casing forms fixed edge fittings, resulting in an increase in manufacturing cost of each of the floating units. Moreover, exterior shape must be changed, and thus are not economical for industrial use.
In addition, in the aforementioned patent, the bottom portions of the longitudinal frame bars or crosswise frame bars are fitted with first load bearing portions and second load bearing portions, which only enable the joining areas between each of the floating units to reinforce rising buoyancy or falling buoyancy of the liquid level of the oil stored in the tank, while joining areas at upper sides of the longitudinal frame bars or the crosswise frame bars are put under stress and deform. In the aforementioned patent, there is no deformation to reinforce the structure between the upper sides of the longitudinal frame bars or the crosswise frame bars and the floating units, thereby easily causing deformation damage to the joining areas between the upper sides of the longitudinal frame bars or the crosswise frame bars and the floating units, and thus greatly diminishing the floating function of the floating mechanism.